I've never used a triple chainring but have now set my mind on a Giant bike with a 53/39/30 and a 10 speed 12/25 at the back.
Having only ever ridden a 52/42 before (impossible for the hilly area where I live!) I was wondering about the issues involved with cross chaining, specifically when using the middle ring of a triple.
Let's say you were going up a hill using your middle ring (39 teeth) and were in your 21 sprocket at the back. Would you still be able to stay in the middle ring and shift down to the 23 and 25 sprockets if the gradient increased, or would the fact that you have a 30 tooth small ring at the front mean that the angle of the chain would be too severe to use the smallest gears whilst on the middle ring?
Obviously on a double chainset you could shift into the 23 and 25 without any worries about the chain angle.
But if you're going up a hill and your bike has a triple, assuming that you are already in 39x21, would it be wiser to shift down to a 30x19 ratio rather than a 39x23?
I guess that there would be similar cross chaining issues at the front using a 39x12 also (not that I could ever see myself using that scenario - I'm just interested to know)?
Many thanks
Having only ever ridden a 52/42 before (impossible for the hilly area where I live!) I was wondering about the issues involved with cross chaining, specifically when using the middle ring of a triple.
Let's say you were going up a hill using your middle ring (39 teeth) and were in your 21 sprocket at the back. Would you still be able to stay in the middle ring and shift down to the 23 and 25 sprockets if the gradient increased, or would the fact that you have a 30 tooth small ring at the front mean that the angle of the chain would be too severe to use the smallest gears whilst on the middle ring?
Obviously on a double chainset you could shift into the 23 and 25 without any worries about the chain angle.
But if you're going up a hill and your bike has a triple, assuming that you are already in 39x21, would it be wiser to shift down to a 30x19 ratio rather than a 39x23?
I guess that there would be similar cross chaining issues at the front using a 39x12 also (not that I could ever see myself using that scenario - I'm just interested to know)?
Many thanks